Glutaminase inhibition impairs CD8 T cell activation in STK11-/Lkb1-deficient lung cancer
Sarah A. Best, Patrick M. Gubser, Shalini Sethumadhavan, Ariena Kersbergen, Yashira L. Negrón Abril, Joshua E. Goldford, Katherine Sellers, Waruni Abeysekera, Alexandra L. Garnham, Jackson A. McDonald, Clare E. Weeden, Dovile Anderson, David Pirman, Thomas P. Roddy, Darren J. Creek, Axel Kallies, Gillian A. Kingsbury, Kate D. Sutherland
Abstract
The tumor microenvironment (TME) contains a rich source of nutrients that sustains cell growth and facilitate tumor development. Glucose and glutamine in the TME are essential for the development and activation of effector T cells that exert antitumor function. Immunotherapy unleashes T cell antitumor function, and although many solid tumors respond well, a significant proportion of patients do not benefit. In patients with KRAS-mutant lung adenocarcinoma, KEAP1 and STK11/Lkb1 co-mutations are associated with impaired response to immunotherapy. To investigate the metabolic and immune microenvironment of KRAS-mutant lung adenocarcinoma, we generated murine models that reflect the KEAP1 and STK11/Lkb1 mutational landscape in these patients. Here, we show increased glutamate abundance in the Lkb1-deficient TME associated with CD8 T cell activation in response to anti-PD1. Combination treatment with the glutaminase inhibitor CB-839 inhibited clonal expansion and activation of CD8 T cells. Thus, glutaminase inhibition negatively impacts CD8 T cells activated by anti-PD1 immunotherapy.